Gil But was kind enough to take pictures of not one, but three BC 2K4sh's that he built simultaneously. I lay claim to one of them, although all are very cool amps and will be proudly positioned in 3 systems!!!

Mine is the brushed stainless job with the knobs on the front and two sets of binding posts for bi-wire. I had him build it to what I wanted and some keen innovation on his part to make my "back of the napkin" desires into reality.

As most know, the BC 2K series amps have a tube option that makes them switchable hybrids. Gil But was very kind in letting me audition a 2K4 which not only sealed the deal on my desire to get a 2K series amp, but also to finally have a BC hybrid amp. The difference with my particular 2K4sh amp is that I chose to take some of the design concepts of the BC 307 preamp (parallel, summing circuits) - but this time in a power amp's input stage. I liked, yet could not afford, a BC 307 for its ultimate sound tailoring capability.

I sent an email off to Gil But and asked "hey, could you put in a circuit like the 307 which would let me blend in/out how much of the 6SN7 tube I wanted in the sound at any particular time?" His reply was "sure, I think I can do that".

What transpired next was true genius. He wrote back and said "would you consider having a knob to dial how much of the solid state you want mixed in too?" (or something like that ). I thought about it and said "why not?" I am really psyched to get it (soon) and not only can I defeat the tube entirely, I can tailor the blending of "tube euphony" (sorry Bob Neill) till the cows come home. Another benefit of the "blender controls" is that I can adjust the gain of the amp dynamically as well, which in its own right is very cool.

This is yet another example of the furtive mind of Gil But Yeung!! I am a happy camper - this amp has BIG shoes to fill. My highly modified BC26 was a really superb amplifier. I will try and post some impressions after it breaks in some and I figure out how to best "tune it" - what a problem to have, eh?

Sounds awesome. It will be nice to have the flexibility of being able to control the level of tube magic in the mix. If there is another audio engineer who will persevere in order to make one's back of the napkin desire into reality (for a sane price), I'd like to know who it is.

Actually, you were my inspiration to upgrade my BC 26 with what you had done to your BC 22. You got nothing to be envious about. The 2K series is a personal choice and at the same time a divergent path to the 200 series amps. It can be absolutely resolving (the stuff Bob talks about) and at the same time humanly personal, like the times when your rig just nails it and nobody is there to agree with you... I have spent some time with the 2k4 and in its natural voice was something that I thought was sublime with 70% of my music, but I would find it hard to live with that ratio for each piece I tee up (given I love the other 30% too). The 2k4 will release an unabashed review of the sound as a reference amp should. Note: PLEASE do NOT view the 2k series amps as bright, thin, analytical or unfriendly; they are not that at all - but, truth be told they are a very clear lens with the "BC signature" mixed in.

IMHO, to these ears, the standard 2K series amps are kind of like "GPS for the music". But in all honesty for some of my challenging recordings, I would find it hard to just sit there and say "wow, the music is really enjoyable and oh boy these warts in the recording are sure nice too". That may work for some folks here, but not me (especially when BC offers alternatives to that "view").

I chose what I chose very specifically. First, I am a big fan of the 6SN7 and being able to use the character of the tube versus frequency attenuation (aka tone controls) was something I found intriguing.

Get yourself one, seriously - or at least try one in your rig like I did. Look, this series especially the way Gil But implements Class D, is examplary but I feel the "sh knob control version" offers all the good bits and flexibility too - at least to me.

Have you heard the O22i and if so, would you willing to do a comparison? They both have their own virtues but I'd love to hear someone other than myself attempt to characterize them. I don't know what your preamp is so of course that would play into this...Actuallly, I guess the more logical comparison would be between the 1022 and 2K4.

Nope, I have not heard the 022i. I don't have a way of auditioning too much audio wise in the Finger Lakes area of NY, so my reference are the amps I have heard (like the BC208's, my modified BC 26, Katlas, 2K4, etc.). I have a BC3000 GZpz SE (basically a 2X GZpz - about as far as you can go in a double height chassis/3.1 before a 303-DWDB). I run (mostly) Siemens 6922 and 7308's which are about as neutral of a tube you can find for that preamp. Our fearless leader was kind enough to loan me the 2k4 prototype and like I said, I instantly became a fan. I like the way my new amp is coming. I can make it more rich or more truthful at the turn of the knob, versus me swapping in some Amperex or Matsushita tubes in the 3000 to do the same. I have plenty of 6SN7's left from my BC21 to play with as well, but I will leave the stock EH model in there for now. Gilbert also put a hole in the back of the chassis so I can do the 2keps when I have the funds. Thanks!

Just for fun this a.m. I put my ELD BD into a system with JMR Bliss Silvers. I hadn't listened to that combo in quite a while and audio memory can fade. I am always surprised at how good GY's Class D stuff sounds and even with the modest ELD I was again surprised. I put in an NOS RCA 5922 (6SN7 variant) and after it warmed up a bit, I liked the amp in tube mode fine but missed the shine in the top end of the violin and the clarity and authority of the low end of the piano. So I haven't "matured" on this subject. I still prefer more to warmish.

The ELD BD is not a 2K4 with or without a K4eps, but it gets GY's Class D sound well enough to make its point. And I still think there are listeners who will prefer the BC Class D sound to the 1022/O22i sound and was just hoping you'd had the experience to explain why you were (likely) one of them.

Thanks for the reply Bob! That is why I went with the "adjustable" version for both SS and tube sections that allow "all one or all another" and permutations of each. The bass on the 2K4 SS is killer; the top end of the 2K4 on "good" recordings is killer. The top end on some of the marginal recordings lets you hear just that - which with some music is a challenging listen (at least to this guy). I figured that having an adjustable way of giving a little warmth when needed was a novel approach versus "tube in" or tube out". I just hope that I am not up and down a lot trying to perfect the imperfect...

Following up my own note above, the longer I listen to the ELD BD on the little Reynauds, the better it gets. The ELD is an easy amp to underrate. It sounds distinctly different from the O22i, so if you're looking at integrateds, don't assume anything, try 'em both.